Allow providing get_schema_kwargs as a function

flask_rest_jsonapi/resource.py

@@ -59,6 +59,31 @@ def __new__(cls):
 
         return super(Resource, cls).__new__(cls)
 
+    def _access_kwargs(self, name, args, kwargs):
+        """
+        Gets the kwargs dictionary with the provided name. This can be implemented as
+        a dictionary *or* a function, so we have to handle both possibilities
+        """
+        # Access the field
+        val = getattr(self, name, dict())
+
+        if callable(val):
+            # If it's a function, call it and validate its result
+            schema_kwargs = val(args, kwargs)
+            if not isinstance(schema_kwargs, dict):
+                raise TypeError(
+                    'The return value of the "{}" function must be a dictionary of kwargs'
+                )
+        else:
+            # If it's a dictionary, use it directly
+            schema_kwargs = val
+            if not isinstance(schema_kwargs, dict):
+                raise TypeError(
+                    'The value of the "{}" class variable must be a dictionary of kwargs'
+                )
+
+        return schema_kwargs
+
     @jsonapi_exception_formatter
     def dispatch_request(self, *args, **kwargs):
         """Logic of how to handle a request"""
@@ -118,7 +143,9 @@ def get(self, *args, **kwargs):
 
         objects_count, objects = self.get_collection(qs, kwargs)
 
-        schema_kwargs = getattr(self, 'get_schema_kwargs', dict())
+        # get_schema_kwargs can be a class variable or a function
+        schema_kwargs = self._access_kwargs('get_schema_kwargs', args, kwargs)
+        schema_kwargs.update()
         schema_kwargs.update({'many': True})
 
         self.before_marshmallow(args, kwargs)
@@ -149,8 +176,9 @@ def post(self, *args, **kwargs):
 
         qs = QSManager(request.args, self.schema)
 
+        schema_kwargs = self._access_kwargs('post_schema_kwargs', args, kwargs)
         schema = compute_schema(self.schema,
-                                getattr(self, 'post_schema_kwargs', dict()),
+                                schema_kwargs,
                                 qs,
                                 qs.include)
 
@@ -230,8 +258,9 @@ def get(self, *args, **kwargs):
 
         self.before_marshmallow(args, kwargs)
 
+        schema_kwargs = self._access_kwargs('get_schema_kwargs', args, kwargs)
         schema = compute_schema(self.schema,
-                                getattr(self, 'get_schema_kwargs', dict()),
+                                schema_kwargs,
                                 qs,
                                 qs.include)
 
@@ -247,7 +276,7 @@ def patch(self, *args, **kwargs):
         json_data = request.get_json() or {}
 
         qs = QSManager(request.args, self.schema)
-        schema_kwargs = getattr(self, 'patch_schema_kwargs', dict())
+        schema_kwargs = self._access_kwargs('patch_schema_kwargs', args, kwargs)
         schema_kwargs.update({'partial': True})
 
         self.before_marshmallow(args, kwargs)

tests/test_sqlalchemy_data_layer.py

@@ -6,7 +6,7 @@
 from sqlalchemy import create_engine, Column, Integer, DateTime, String, ForeignKey
 from sqlalchemy.orm import sessionmaker, relationship
 from sqlalchemy.ext.declarative import declarative_base
-from flask import Blueprint, make_response, json
+from flask import Blueprint, make_response, json, Flask
 from marshmallow_jsonapi.flask import Schema, Relationship
 from marshmallow import Schema as MarshmallowSchema
 from marshmallow_jsonapi import fields
@@ -457,6 +457,7 @@ def register_routes(client, app, api_blueprint, person_list, person_detail, pers
     api.route(string_json_attribute_person_detail, 'string_json_attribute_person_detail',
               '/string_json_attribute_persons/<int:person_id>')
     api.init_app(app)
+    return api
 
 
 @pytest.fixture(scope="module")
@@ -647,6 +648,58 @@ def test_get_list_disable_pagination(client, register_routes):
         response = client.get('/persons' + '?' + querystring, content_type='application/vnd.api+json')
         assert response.status_code == 200
 
+def test_get_list_class_kwargs(session, person, person_schema, person_model, computer_list):
+    """
+    Test a resource that defines its get_schema_kwargs as a dictionary class variable
+    """
+    class PersonDetail(ResourceDetail):
+        schema = person_schema
+        data_layer = {
+            'model': person_model,
+            'session': session,
+            'url_field': 'person_id'
+        }
+
+        get_schema_kwargs = dict(
+            exclude=['name']
+        )
+
+    app = Flask('test')
+    api = Api(app=app)
+    api.route(PersonDetail, 'api.person_detail', '/persons/<int:person_id>')
+    api.route(computer_list, 'api.computer_list', '/computers', '/persons/<int:person_id>/computers')
+    api.init_app(app)
+
+    ret = app.test_client().get('/persons/{}'.format(person.person_id))
+
+    assert 'name' not in ret.json['data']['attributes']
+
+def test_get_list_func_kwargs(session, person, person_schema, person_model, computer_list):
+    """
+    Test a resource that defines its get_schema_kwargs as a function
+    """
+    class PersonDetail(ResourceDetail):
+        schema = person_schema
+        data_layer = {
+            'model': person_model,
+            'session': session,
+            'url_field': 'person_id'
+        }
+
+        def get_schema_kwargs(self, args, kwargs):
+            return dict(
+                exclude=['name']
+            )
+
+    app = Flask('test')
+    api = Api(app=app)
+    api.route(PersonDetail, 'api.person_detail', '/persons/<int:person_id>')
+    api.route(computer_list, 'api.computer_list', '/computers', '/persons/<int:person_id>/computers')
+    api.init_app(app)
+
+    ret = app.test_client().get('/persons/{}'.format(person.person_id))
+
+    assert 'name' not in ret.json['data']['attributes']
 
 def test_head_list(client, register_routes):
     with client: